A method for rapid drying of sizing agents during the production of glass fibers

Abstract

This invention relates to a rapid drying method for sizing agents during glass fiber production, comprising the following steps: 1) Glass fibers are guided by a fiber guiding device into a sizing device for sizing treatment; 2) After sizing, the glass fibers pass through a tension sensor and sequentially enter a preheating zone and an evaporation zone; infrared emitters in the preheating and evaporation zones heat the glass fibers to dry the sizing agent; 3) Sensors in the preheating and evaporation zones measure the surface temperature and humidity of the glass fibers in real time; 4) The output power of the infrared emitters is dynamically adjusted based on the detected temperature and humidity signals and the winding speed of the winding device to achieve closed-loop control of the glass fiber drying process. This invention improves drying efficiency and reduces energy consumption, demonstrating significant industrial application value for energy saving and consumption reduction in glass fiber production lines.

Description

Technical Field

[0001] This invention relates to a drying method, specifically a rapid drying method for sizing agents used in glass fiber production, and belongs to the field of glass fiber drying technology. Background Technology

[0002] In traditional glass fiber drawing production, the sizing agent (a water-based mixture consisting of film-forming agents, adhesion promoters, and additives) needs to be dried for a long time in a convection drying oven or infrared oven after drawing to remove moisture. This process is time-consuming and energy-intensive, and has the following main drawbacks:

[0003] 1. Low thermal efficiency: During the hot air drying process, about 80% of the heat energy is used to heat the air rather than the glass fiber itself, with a thermal efficiency of less than 15%. During the glass fiber winding process, the temperature difference between the core and the surface of the cylinder causes the glass fiber to "shell", resulting in up to 30% of the products having defects such as yarn separation or delamination.

[0004] 2. Severe fluid migration: During the glass fiber winding process, residual moisture easily migrates from the core to the outer layer, resulting in a difference of up to 400% in the concentration of sizing agent components between the core and the surface of the core, which in turn affects the mechanical properties of the composite material.

[0005] 3. Rigid drying cycle: Traditional processes require a long drying time (generally 6 to 24 hours) to meet the drying requirements, which cannot flexibly adapt to different sizing formulas and production speeds, resulting in low production efficiency and a large footprint.

[0006] 4. High energy consumption: According to statistics, about 45% of the downstream energy consumption in traditional glass fiber production lines comes from the fiber drying process.

[0007] Therefore, in order to solve the above problems, it is indeed necessary to provide an innovative method for rapid drying of sizing agents during glass fiber production to overcome the defects in the prior art. Summary of the Invention

[0008] The purpose of this invention is to provide a rapid drying method for sizing agents during glass fiber production. This method integrates an infrared emitter between the sizing and winding processes to dry the sizing agent before the glass fiber is wound, thereby improving production efficiency and reducing energy consumption.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for rapid drying of sizing agent during glass fiber production, which employs a drying device, the drying device comprising a fiber guiding device, a sizing device, a tension sensor, a preheating zone, an evaporation zone, and a winding device arranged in sequence.

[0010] The online rapid drying method includes the following steps:

[0011] 1) Glass fibers are guided by a fiber guiding device and enter a sizing device for sizing treatment;

[0012] 2) After sizing, the glass fibers pass through the tension sensor and then enter the preheating zone and evaporation zone in sequence; the glass fibers are heated by infrared emitters in the preheating zone and evaporation zone to dry the sizing agent;

[0013] 3) Sensors in the preheating and evaporation zones measure the surface temperature and humidity of the glass fiber in real time;

[0014] 4) By detecting temperature and humidity signals and the winding speed of the winding device, the output power of the infrared emitter is dynamically adjusted to achieve closed-loop control of the glass fiber drying process.

[0015] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: in step 2), the radiation peak value of the infrared emitter is 1300 nm; the infrared heating power density range is 1–5 W / cm². 2 .

[0016] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: the preheating zone and the evaporation zone have the same structure; a reflective cavity is provided in both the preheating zone and the evaporation zone; the reflective cavity is cylindrical and uses an aluminized plate or metallized ceramic as the inner wall.

[0017] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: the sensors in the preheating zone and the evaporation zone both include an infrared thermometer and an infrared moisture meter.

[0018] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: in step 4), the output power of the infrared emitter is the sum of the reference power and various correction values:

[0019]

[0020] in, This refers to the output power of the infrared transmitter; = A represents the preheating zone, =B represents the evaporation zone; Set the power based on the baseline; Base power correction; This indicates the amount of power correction for feedforward compensation; Indicates the power fuzziness correction amount; The power driver of the corresponding infrared transmitter is sent to adjust the output power of the infrared transmitter in real time.

[0021] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: the basic power correction amount

[0022] First, calculate the temperature and humidity deviations:

[0023]

[0024]

[0025] in, To set the target temperature, Let be the measured temperature at time t; To set the target moisture content, Let be the measured moisture content at time t; These are the temperature deviation and humidity deviation, respectively; the calculated values ​​are... This will serve as the input parameter for the next step of PID control and fuzzy logic control;

[0026] Then calculate the base power correction amount separately. :

[0027]

[0028] in, A weighted combination of temperature deviation or humidity deviation is used. , , These are the proportional, integral, and differential coefficients, respectively, and their ranges of value are as follows: ∈ [0.5, 1.5], ∈ [0.01, 0.1], ∈ [0.005, 0.05]; It is a correction amount for the set power, which will serve as the basis input for subsequent feedforward compensation and fuzzy logic correction.

[0029] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: the feedforward compensation power correction amount The specific calculation method is as follows:

[0030]

[0031] in, This indicates the amount of power correction for feedforward compensation, in W, used to correct for differences in dwell time caused by variations in linear velocity. The change in winding linear speed is expressed in m / min. Forward coefficients, ∈ [0.05, 0.2] W·min / m.

[0032] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: the power fuzzy correction amount The following method is used for calculation:

[0033] When temperature deviation and moisture content deviation Simultaneously, upon reaching a preset threshold, the fuzzy logic module is triggered, and based on the temperature deviation... and moisture content deviation linear velocity change rate Perform fuzzy inference to calculate power correction. .

[0034] The rapid drying method for the sizing agent during glass fiber production of the present invention further comprises: the fuzzy inference rule specifically being:

[0035] a. If the moisture content is high And the linear velocity increases rapidly. >50m / min 2 This increases the power of the evaporation zone. =+20 +30 ;

[0036] b. If the temperature is too high This reduces the power of the preheating zone. ;

[0037] c. If the moisture content is close to the target and the temperature is close to the target. ≈ 0 and If approximately 0, then no correction is needed. = 0;

[0038] d. If the linear velocity drops suddenly 50m / min 2 ,but ;

[0039] e. If the humidity is high but the temperature is close to the target... and If the value is approximately 0, then the power of the evaporation zone should be increased first. =+10 +20 .

[0040] The rapid drying method of the sizing agent during glass fiber production of the present invention further comprises: one or more infrared emitters are provided in the preheating zone and the evaporation zone, and each infrared emitter can independently adjust its power, specifically a high-frequency short-wave infrared device.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The rapid drying method for sizing agent during glass fiber production of the present invention, by setting an infrared emitter, can rapidly evaporate the moisture on the surface of the glass fiber in a very short time, thereby achieving rapid drying of the glass fiber before it is wound.

[0043] 2. The rapid drying method for sizing agents during glass fiber production of the present invention combines multi-zone heating, a reflective cavity focusing structure, non-contact temperature and humidity sensing, and a closed-loop power adjustment strategy to ensure the uniformity and controllability of drying. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the drying equipment used in this invention.

[0045] Figure 2 yes Figure 1 A schematic diagram of the structure of the preheating zone and the evaporation zone.

[0046] Figure 3 This is a flowchart of a rapid drying method for sizing agents during glass fiber production according to the present invention.

[0047] Figure 4 This is a flowchart of the closed-loop control algorithm based on temperature and humidity feedback and linear velocity compensation in step 4) of the present invention. Detailed Implementation

[0048] Please refer to the instruction manual appendix. Figure 1 and attached Figure 2 As shown, this is a drying device used in a rapid drying method for sizing agents during glass fiber production according to the present invention. The drying device consists of several parts arranged in sequence, including a fiber guiding device 1, a sizing device 2, a tension sensor 3, a preheating zone 4, an evaporation zone 5, and a winding device 6.

[0049] The fiber guiding device 1 is used to transport glass fibers along a predetermined path. Sizing is performed when the glass fibers are transported to the sizing device 2.

[0050] The tension sensor 3 is used to detect the tension of the glass fiber. It works in conjunction with the fiber guiding device 1 to ensure stable delivery and tension control of the glass fiber, providing a consistent initial state for subsequent drying.

[0051] The preheating zone 4 and evaporation zone 5 are used for zoned infrared irradiation of the glass fiber, and the heating of the two zones is independently controlled so that the radiation power can be adjusted according to the position of the glass fiber. In this embodiment, the preheating zone 4 and evaporation zone 5 have the same structure; both the preheating zone 4 and evaporation zone 5 are provided with a reflective cavity 7. The reflective cavity 7 is cylindrical and uses an aluminized plate or metallized ceramic as the inner wall. The reflective cavity 7 can reflect and focus infrared radiation to enhance the focusing and utilization of infrared radiation, reduce heat radiation loss to the environment, and thus further improve irradiation efficiency and drying efficiency.

[0052] Furthermore, the preheating zone 4 and evaporation zone 5 are equipped with one or more infrared emitters 8, each with independently adjustable power. Specifically, each emitter 8 is a high-frequency short-wave infrared device used for rapid and uniform drying of glass fibers containing high-moisture sizing agents. Simultaneously, the high-frequency short-wave infrared radiation effectively improves the optical coupling efficiency with water molecules in the glass fibers. In this embodiment, the radiation peak of the infrared emitter 8 is 1300 nm, which selectively heats the glass fibers and sizing agents while heating the air with minimal effect, thereby rapidly evaporating moisture before the glass fibers are wound and formed.

[0053] The infrared heating power density range of the infrared emitter 8 is selected to be 1–5 W / cm². 2 This range is determined based on energy balance calculations of the heat required for moisture evaporation during glass fiber sizing, combined with the commonly used surface power of existing industrial near-infrared drying equipment. Experiments show that when the power density is below 1 W / cm²... 2 Insufficient drying time, exceeding 5 W / cm 2 Rapid temperature rise on the fiber surface can cause sizing ablation, therefore a temperature of 1–5 W / cm was selected. 2 As a preferred range, it ensures rapid drying and avoids overheating damage.

[0054] The preheating zone 4 and the evaporation zone 5 are further equipped with sensors 9. The sensors 9 are non-contact sensors that measure the surface temperature and moisture content of the glass fiber in real time. Specifically, they are infrared thermometers and infrared moisture meters. These infrared sensors work in a non-contact manner and can continuously scan or measure the passing glass fiber, transmitting the temperature and humidity data to the control system in real time.

[0055] Please refer to the instruction manual appendix. Figure 3 As shown, the rapid drying method for sizing agents during glass fiber production using the above-mentioned drying equipment includes the following steps:

[0056] 1) Glass fibers are guided by fiber guiding device 1 and enter sizing device 2 for sizing treatment.

[0057] 2) After sizing, the glass fibers pass through tension sensor 3 and then sequentially enter preheating zone 4 and evaporation zone 5. The glass fibers are heated by infrared emitters 8 in preheating zone 4 and evaporation zone 5 to dry the sizing agent. Since the output power of each heating zone (preheating zone 4 and evaporation zone 5) can be controlled independently, the emission intensity can be adjusted segment by segment according to the position of the glass fibers and the drying requirements to avoid overheating or underheating.

[0058] 3) Sensors 9 in the preheating zone 4 and evaporation zone 5 measure the surface temperature and humidity of the glass fiber in real time.

[0059] 4) By detecting temperature and humidity signals and the winding speed of the winding device, the output power of the infrared emitter is dynamically adjusted to achieve closed-loop control of the glass fiber drying process. Specifically, the control system dynamically adjusts the output power of each infrared emitting unit based on the winding speed and sensor feedback signals using PID or fuzzy control algorithms, keeping the surface temperature and humidity of the glass fiber within the set target range. This closed-loop control strategy can automatically compensate for the effects of changes in glass fiber diameter or differences in sizing formulation, thereby ensuring drying consistency throughout the entire winding process.

[0060] Please continue to refer to the instruction manual appendix. Figure 4 As shown, the output power of the infrared emitter is the sum of the reference power and various correction values:

[0061]

[0062] in, This refers to the output power of the infrared transmitter; = A represents the preheating zone, =B represents the evaporation zone; Set the power based on the baseline; Base power correction; This indicates the amount of power correction for feedforward compensation; Indicates the power fuzziness correction amount; The power driver sent to the corresponding infrared transmitter adjusts the output power of the infrared transmitter in real time. This formula combines a base power with multiple correction parameters to ensure rapid and uniform drying of the glass fiber before winding.

[0063] Furthermore, the base power correction amount

[0064] First, calculate the temperature and humidity deviations:

[0065]

[0066]

[0067] in, To set the target temperature, Let be the measured temperature at time t; To set the target moisture content, Let be the measured moisture content at time t; These are the temperature deviation and humidity deviation, respectively; the calculated values ​​are... This will serve as the input parameter for the next step of PID control and fuzzy logic control;

[0068] Then calculate the base power correction amount separately. :

[0069]

[0070] in, A weighted combination of temperature deviation or humidity deviation is used. , , These are the proportional, integral, and differential coefficients, respectively, and their ranges of value are as follows: ∈ [0.5, 1.5], ∈ [0.01, 0.1], ∈ [0.005, 0.05]; It is a correction amount for the set power, which will serve as the basis input for subsequent feedforward compensation and fuzzy logic correction.

[0071] To compensate for the change in dwell time caused by the change in linear velocity, feedforward compensation is implemented, wherein the feedforward compensation power correction amount The specific calculation method is as follows:

[0072]

[0073] in, This indicates the amount of power correction for feedforward compensation, in W, used to correct for differences in dwell time caused by variations in linear velocity. The change in winding linear speed is expressed in m / min. Forward coefficients, ∈ [0.05, 0.2] W·min / m.

[0074] The power fuzzy correction amount The following method is used to calculate: when the temperature deviation and moisture content deviation Simultaneously, upon reaching a preset threshold, the fuzzy logic module is triggered, based on the temperature deviation. and moisture content deviation linear velocity change rate Perform fuzzy inference to calculate power correction. .

[0075] Furthermore, the fuzzy inference rule is specifically as follows:

[0076] a. If the moisture content is high And the linear velocity increases rapidly. >50m / min 2 This increases the power of the evaporation zone. =+20 +30 ;

[0077] b. If the temperature is too high This reduces the power of the preheating zone. ;

[0078] c. If the moisture content is close to the target and the temperature is close to the target. ≈ 0 and If approximately 0, then no correction is needed. = 0;

[0079] d. If the linear velocity drops suddenly 50m / min 2 ,but ;

[0080] e. If the humidity is high but the temperature is close to the target... and If the value is approximately 0, then the power of the evaporation zone should be increased first. =+10 +20 .

[0081] Through the above steps, the glass fiber is rapidly dried before being wound, eliminating the need for lengthy traditional oven processing. Furthermore, the rapid drying method of this invention significantly improves drying efficiency and reduces energy consumption. For example, tests on polyvinyl acetate-based sizing agents show that, while the conventional process consumes 4.8 kWh / kg, the method of this invention reduces unit energy consumption to 0.9 kWh / kg, increasing drying efficiency by approximately 8 times; at an industrial speed of 1200 m / min, the residual moisture content of the polymer-based sizing agent is reduced to below 2%; simultaneously, energy consumption is reduced by approximately 20%, sizing agent migration waste is reduced by nearly 90%, and the traditional 6-hour drying step is eliminated, making production line operation more flexible and faster.

[0082] The above-described specific embodiments are merely preferred embodiments of this invention and are not intended to limit this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A method for rapid drying of a sizing agent during the production of glass fibers, characterized by: The application adopts a drying device which comprises fiber guiding device, sizing device, tension sensor, preheating zone, evaporation zone and winding device arranged in sequence; The online rapid drying method comprises the following steps: 1) The glass fiber is guided by the fiber guiding device and enters the sizing device for sizing treatment; 2) The sized glass fiber enters the preheating zone and evaporation zone in sequence after passing through the tension sensor; the infrared emitter in the preheating zone and evaporation zone heats the glass fiber so as to dry the sizing agent; 3) The sensor in the preheating zone and evaporation zone measures the surface temperature and humidity of the glass fiber in real time; 4) The output power of the infrared emitter is dynamically adjusted according to the detected temperature, humidity signal and winding speed of the winding device, so as to realize closed-loop control of the glass fiber drying process; The output power of the infrared emitter is the sum of the reference power and each correction amount: Wherein, is the output power of the infrared emitter; = A represents the preheating zone, = B represents the evaporation zone; is the basic set power; is the basic power correction amount; represents the feedforward compensation power correction amount; represents the power ambiguity correction amount; will be sent to the power driver corresponding to the infrared emitter, and the output power of the infrared emitter will be adjusted in real time; The base power correction amount First, the temperature and humidity deviation is calculated: wherein, is a set target temperature, is a measured temperature at time t; is a set target moisture content, is a measured moisture content at time t; are a temperature deviation and a moisture deviation, respectively; and is an input parameter for the next PID control and fuzzy logic control. The base power correction amount is calculated again : wherein, a weighted combination of temperature deviation or humidity deviation is adopted, , , are proportional, integral and differential coefficients respectively, and the value ranges are respectively: ∈ [0.5, 1.5], ∈ [0.01, 0.1], ∈ [0.005, 0.05]; is a correction amount for the set power, which will be the basis input for subsequent feedforward compensation and fuzzy logic correction. The feedforward compensation power correction amount The specific calculation method is: wherein, represents a feedforward compensation power correction amount, unit W, for correcting the residence time difference caused by the linear speed change; is the winding linear speed change amount m / min; is the feedforward coefficient, ∈ [0.05, 0.2] W·min / m; The power ambiguity correction amount Is calculated using the following method: When temperature deviation and humidity deviation reach preset threshold, trigger fuzzy logic module, according to temperature deviation and humidity deviation , linear speed change rate , fuzzy inference to calculate power correction .

2. The method of rapid drying of a sizing agent during the production of glass fibers according to claim 1, characterized in that: In the step 2), the radiation peak of the infrared emitter is 1300 nm; the infrared heating power density range is 1-5 W / cm 2 .

3. The method of rapid drying of a sizing agent during the production of glass fibers according to claim 1, characterized in that: The preheating zone and evaporation zone have the same structure; the preheating zone and evaporation zone are both provided with a reflecting cavity; the reflecting cavity is in a cylindrical shape and adopts aluminized plate or metalized ceramic as the inner wall.

4. The method of rapid drying of a sizing agent during the production of glass fibers according to claim 1, characterized in that: The sensor in the preheating zone and evaporation zone both comprises infrared temperature measuring instrument and infrared moisture meter.

5. The method of rapid drying of a sizing agent during the production of glass fibers according to claim 1, characterized in that: The preheating zone and evaporation zone are provided with one or more infrared emitters, and each infrared emitter can independently adjust the power, which is specifically high-frequency short-wave infrared device.

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